Absorbent articles for personal hygiene, such as disposable diapers for infants, training pants for toddlers or adult incontinence undergarments are designed to absorb and contain body exudates, in particular large quantity of urine. These absorbent articles comprise several layers providing different functions, for example a topsheet, a backsheet and an absorbent core, among other layers. Absorbent articles should be able to absorb a large amount of fluid while preventing the fluid from leaking.
These absorbent articles may typically comprise elasticized containment elements at their longitudinal sides that help maintaining the article in contact with the body. Thus it usual for modern diaper to comprise raised flaps, typically referred to as barrier leg cuffs (or more simply “barrier cuffs”) which improve the containment of fluid in the leg-torso joint regions. Each barrier leg cuff may typically comprise one or more elastic strings but some simpler articles have barrier leg cuffs which are not elasticized. Another type of containing elements commonly found in diapers is referred to as gasketing cuffs. Gasketing cuffs typically comprise one or more elastic string or elasticized element inserted in the chassis of the diaper, for example between the topsheet (and/or an extension of the barrier leg cuff material) and the backsheet, in the area of the leg openings to provide an effective seal while the diaper is in use.
Many patents have proposed improvement to these containment elements. For example U.S. Pat. No. 4,808,178 and U.S. Pat. No. 4,909,803 (Aziz) describe disposable diapers having such raised elasticized flaps referred to herein as barrier leg cuffs. U.S. Pat. No. 4,695,278 (Lawson) and U.S. Pat. No. 4,795,454 (Dragoo) describe disposable diapers having dual cuffs, including gasketing cuffs and barrier leg cuffs. U.S. Pat. No. 4,704,116 (Enloe) discloses an absorbent garment comprising a pair of gasketing cuffs and a pair of barrier leg cuffs which attached to or formed from the topsheet and spaced inwardly from said elasticized leg openings, defining a waste-containment pocket.
Different solutions have been proposed to attach the barrier leg cuffs to the chassis of the diapers. U.S. Pat. No. 4,795,454 (Dragoo) teaches attachment means such as an adhesive or heat/pressure sealing, ultrasonic bonding. Seal means such as an adhesive bead are further provided to present a barrier to the wicking of liquids through the topsheet. The seal means are said to prevent liquids from wicking underneath the barrier leg cuffs to the edges of the diaper. The seal means are positioned more inwardly of the diaper than the attachment means. U.S. Pat. No. 7,189,219 (Kasai) discloses creating liquid shut-off regions between the leg cuffs and the topsheet using a heat-seal.
The use of adhesive to attach the barrier leg cuffs to the rest of the article may however increase costs, be less environmentally friendly, and adhesive can come in contact with the wearer's skin. It has also been proposed to attach the barrier leg cuffs to the rest of the absorbent article using mechanical and/or heat bonding. Although this has the advantage of not requiring the use of adhesive, it has however the drawback that undesired holes may be pierced through the bonded materials while joining them. The unwanted holes thus formed may compromise the liquid restraining function of the barrier leg cuffs. The inventors have found that this is especially a problem for materials having a relatively low combined basis weight of less than 60 gsm and/or having a large basis weight variation. US 2011/0196332 (Cheng) addresses partially this problem by suggesting a new barrier leg cuff material comprising two nonwoven component layers, one component layer comprising fibers having a number-average diameter less than about 1 micron, and having a local basis weight variation of less than about 10%. However this material may be more complex and costly to manufacture than conventional nonwoven barrier material, and while reducing the number and size of holes, it does not completely eliminate their occurrence.
Although the prior art has suggested many technical solutions, there is still a need for a simple and cost-effective way to make and attach barrier leg cuffs to the rest of the absorbent article without disrupting their barrier function in the area of bonding. The present inventors are now suggesting a simple and cost effective way to solve this problem.